How to Read a
Vernier Caliper

Vernier calipers are the most reliable measuring tools compared to dial
calipers and digital calipers. Unlike dial calipers and digital calipers,
Vernier calipers can be exposed to coolant, oil, water and dust without worrying
about damaging any internal working parts. But it will definitely test your
eyesight to read the vernier.

Inch Reading

The upper scale reads in inches. Each bar graduation on the main scale is
.025”. Every 8th graduation (.200”) is numbered . Each graduation on
the vernier scale is 0.001”. Every 5th graduation (.005) is
numbered.

For the correct reading, in the picture below, the measurement of .839 is
determined by reading .825” on the main scale (.800 + 1 bar (1x.025=.025) =.825”
). Then add .014 as determined by the reading of the vernier. The graduation on
the vernier that best lines up with the graduation on the main scale is the
correct reading.

Metric Reading

The lower scale reads in metric. Each bar graduation on the main scale is
1mm. Every 10th graduation is numbered (1 cm = 10 mm) . Each vernier
graduation is 0.02mm. Every 5th graduation (.1mm) is numbered.

In the above example, the measurement of 21.32 millimeters is determined by
reading 2.1cm (21mm) on the main scale, and then adding 0.32mm as determined by
the vernier. Again, the graduation on the vernier that best lines up with the
graduation on the main scale is the correct reading.